The mount_ffs command attaches the Berkeley Fast
File System on the special device on to the
file system tree at point node.

This command is invoked by mount(8)
when using any of the following syntax:

mount
[options] specialnode

mount [options] -t ffs
specialnode

The special device is either a
disklabel(8) UID (DUID) or an
entry in /dev. If it is a DUID, it will be
automatically mapped to the appropriate entry in
/dev. In either case the partition must be
present in the disklabel loaded from the device. The partition name is the
last letter in the entry name. For example, /dev/sd0a and 3eb7f9da875cb9ee.a
both refer to the ‘a’ partition.

This command is normally executed per file system by
rc(8) at boot time using the
mount(8) command. The options are
as follows: